Caisson



April 5, 1937- vv. R MARsDl-:N 2,076,379

CAISSON Filed Feb. 8, 1935 2 sheets-Sheet 1 6 o (s Fit] 1 NVENTOR W/z Mw l?. Mms any BY TTORNEY April 6,

W. R. MARsDi-:N 2,076,379

CAISSON Filed Feb. 8, 1955 2 Sheets-Sheet 2 A TTORNEY Patented Apr. 6, 1937 UNITED STATES www PATENT OFFICE 4 Claims.

This invention relates to new and useful improvements pertaining to methods of subsurface construction work, and particularly to those types used for subsurface foundations where the presence of heavy earth and hydrostatic pressures complicate the sinking of caissons to stable strata.

Various methods are employed in caisson construction. One is the open caisson method where usually a caisson form or cylinder .is gradually sunk to a firm foundation by a combination of excavating the earth on the inside of the cylinder or form by machine or man power, and a forcing down of the cylinder or form by weight or` other mechanical means. This type of caisson has a limited field of use.

Another is the pneumatic method where sand hogs working under air pressure, dig the earth out at the bottom of the working chamber, which with its overhead attached caisson penetrates the earth while digging proceeds. Heavy weights are usually located on top of the caisson to counteract compressed air uplift in the caisson and to overcome frictional resistance to penetration by contact of the caisson and the earth walls.

StillA another is` the sol-called mud method, where a hole is made in the earth by a boring tool, and a mud content of artificially regulated consistency is left in the hole until nal boring penetration is reached. This mud content in the unprotected hole aids in preventing excessive caving in of the earth walls of the hole during the boring process. When final penetration depth is reached, the permanent caisson form is forced through the mud, the mud is removed, the caisson form is cleaned out, and the concrete is deposited.

It is the object of my invention so to construct caissons and the like, to reduce the cost and facilitate the practicing of present caisson methods by the use of a specially designed machine.

The invention is illustrated in the accompanying drawings in which- Fig. 1 shows a side elevation partly in crosssection of the caisson constructor, with the caisson cylinder and its cutting section in position and with power hammers bearing on top of the caisson cylinder;

Fig. 2 shows a caisson cylinder as used without a separate cutting section;

Fig. 3 shows a sectional plan view on line I-I of Fig. 4;

Fig. 4 shows a view of the structure illustrated in Fig. l taken from the front, with sectional view of the caisson cylinders; and

Fig. 5 shows as much of an arrangement like the one shown in Fig. 1 as is necessary for one (Cl. Z55-19) skilled in the art, and in which a movable platform bears on top of the caisson cylinder.

In these drawings, like reference numerals indicate like parts throughout the several figures.

I is a bed frame resting on transporting parts 2 such as rollers, skids, caterpillar tractors or the like. This bed frame supports the operating power equipment (not shown) or, the power equipment can be supported on a platform 4. The front edge of the bed frame I supports a vertical tower on legs 5 and 6 with the necessary structural bracing and supports. This tower has a movable platform 4 with sliding guides 20 in contact with legs 5 and 6 so as to permit raising and lowering of the platform to accommodate its elevation to suitable operating'conditins. The purposes of this tower are to support the necessary operating machinery; to act as a guide for boring and caisson revolving apparatus, and to rest as a weight on top of the caisson as an aid in forcing the H caisson into the earth.

Speed reduction gearing is used between a source of power such as a motor (not shown), and a main gear 9 through which passesa verti` cal drive keyed shaft of hollow steel 3. The shaft is made up of two or more parts, so designed as to telescope one within the other for the purpose of providing a variable boring range. On the inside of this hollow shaft, a steel cable 'I is attached at the lower end of the shaft with a swivel connection. The cable runs up through the center of the shafting to sheaves 8 located on top of the tower and hence to the engine drum (not shown).

On the lower section of this shafting and intermediate its length, metal arms I0 are attached which connect with fittings II fastened to the inside of a revolving cylinder I2 or I5 for the purpose of transmitting circular motion to the cutting edge of the cylinder. These arms are of adjustable length so as to be adaptable to use in caisson cylinders of Variable diameters.

A boring tool I3 is attached to the lower end of shafting 3 to loosen the earth inside the cylinder. The arms of this boring tool are adjustable in lengthI so as to bore the earth over a required radius.

In accordance with my invention the caisson cylinder is revolved as a unit consisting of I5, Fig. 2, or a main cylinder I4 and an auxiliary revolving and cutting cylinder I2 (Fig. 1). 'Ihe cutting cylinder I2 can be of any desired length, and of a diameter to allow to the next upper section of the caisson cylinder I4 vertical play inside it. On the bottom edge o1 cylinder I4 and intermediate its length, metal rings I8 are provided. At the top edge of cutting cylinder I2 and intermediate its length metal rings I1 are provided. These rings act as a seal between the two caisson cylinder sections; they prevent separation of the two sections of the cylinder one from the other, and they act as a pulling down or a driving down connection for one or the other of these sections.

I use a combination of methods to cause the caisson cylinders to penetrate the earth; the cylinder I5 may be rotated; the main cylinder I4 may be pulled down by the rotating cutting section I2; and compressed air hammers I6 acting on top of the cylinder may be used. In the modification shown in Fig. 5, vthe caisson is caused to penetrate the earth by the weight of the platform 4 resting on top of cylinder I4.

In general, the operations in constructing a caisson by my method are as follows: The caisson constructor being placed at caisson location, the caisson cylinder with or without a separate cutting section as conditions necessitate, is placed in position in front of the caisson constructor. The boring and revolving apparatus I0 and I3 is lowered by shaft 3 to the earth inside the cylinder and the arms I0 hooked up to fittings II on the cylinder. Power is transmitted through the gear 9 t0 the drive shaft 3, hence to the cylinder revolving arms I0 and the cylinder, and to the boring tool I 3. The revolving cutting edge of the-cylinder penetrates the earth and at the same time the boring tool I3, in conjunction with water introduced when necessary, loosens the earth inside the cylinder.

Penetration may proceed throughout the length of the caisson if practical, or the penetration process may be stopped at any point in the caisson length, the boring and revolving apparatus quickly raised by use of the telescoping shafts, and the loosened earth removed by any of the excavating methods in common use.

In the penetration of earth, boulders, hardpan or other obstructions may be encountered. A cylinder cutting edge I9 with a cutting shape of special cutting steel may be used, or the cutting edge may be used in combination with a shot coring method, where chilled steel shot is introduced to the revolving cutting edge of the cylinder to sever obstructions, so that the interfering portion can be removed. The cutting edge grooves a seat for the bottom edge of the caisson cylinder in the final strata.

When final penetration is reached, the caisson cylinder is excavated, cleaned out and filled with concrete.

I believe my invention to be susceptible of embodiment and capable of practice by other means than those specifically illustrated and described, and therefore do not intend to be understood as limiting it thereto, save as defined in the appended claims.

What I claim is:

l. In a machine for subsurface construction work, a cylindrical caisson having a lower cutting revolving section and a contiguous upper section, a limited sliding connection between said sections, a telescoping hollow shaft for revolving the lower section, adjustable metal arms mounted on s aid shaft engaging the cutting section, and a boring tool mounted on the lower end of said hollow shaft.

2. In a machine for subsurface construction work, a cylinder having an upper and a lower section, a coupling between said sections whereby one will cause vertical displacement of the other, a telescoping shaft projecting through said cylinder sections and rotating the lower section,`

and a vertically movable platform for applying Vertical force to the upper section.

3. In a machine for subsurface construction work, a cylindrical caisson, a telescoping hollow shaft for revolving said caisson, and adjustable metal arms mounted on said shaft and engaging said caisson.

4. In a machine in accordance with claim 3, and a boring tool mounted on the lower end of said telescoping hollow shaft.

WILLIAM R. MARSDEN. 

